An Efficient One-Pot Synthesis Of 2-Bromo-6-Aryl[5h]Pyrrolo[2,3-B]Pyrazines

We report a two step one-pot method for the synthesis of 2-bromo-6-aryl[5H]pyrrolo[2,3-b]pyrazines. The process makes use of a cleaner copper-free Sonogashira coupling and an improved base-mediated 5-exo-dig cyclisation to afford the products in good yields. This method expands the scope to structures that are poorly represented in the literature and incorporates a halide for further synthetic elaboration. (C) 2015 Elsevier Ltd. All rights reserved.